Unit 3 Flashcards
primary endosymbiosis is a synapomorphy of the (blank)
kingdom plantae
(blank) are aquatic photosynthetic eukaryotes
algae
land plants arose how many years ago?
450-500 mya
challenges of plants
1) dessication (drying out)
2) water/nutrient transport and support
3) distribute gametes and progeny
dessication challenge
- cuticle
- stomata
- spores
- antheridia/archegonia
- embryos protected
waxy coating slows water loss
cuticle
regulate gas exchange
stomata
spores
gametophyte
antheridia
male gamete
archegonia
female gamete
water/nutrient transport; support challenge
- don’t get too big
- vascular structures
nonvascular plants distribute gametes
moss= flagella (need H2O)
nonvascular plants progeny
haploid spores (wind)
vascular plants distribute gametes
fern= flagella (need H2O)
vascular plants progeny
haploid spores (wind)
vascular seeds distribute gametes
conifer=pollen (wind)
vascular seeds progeny
diploid seeds (wind, seed pollinator)
vascular seeds with flowers distribute gametes
pollen (wind/pollinators)
vascular seeds with flowers progeny
diploid seeds (wind, seed pollinators)
what were early helpers of land plants?
fungi
mutualistic fungi date to
460 mya
mutualistic fungi aid with
absorption of water and minerals
a synapomorphy of land plants is an (blank) protected by tissues of the parent plant
embryo
- 9000 species
- gametophyte dominant
- also reproduce asexually
liverworts
How do liverworts reproduce asexually?
- by fragmentation of the gametophyte
- by gemmae, dispersed by raindrops
- 15,000 species
- have stomata
- gametophytes begin as branched filamentous structures
- peat
- bogs
mosses
what is the stomata important for?
H2O and gas exchange
branched filamentous structures
protonema
sphagnum moss grows in
cool, swampy places
compression of moss leads to (blank) which leads to (blank)
peat, coal
(blank) develop where peat builds up over time
bogs
- 100 species
- gametophytes are flat plates of cells
hornworts
vascularity evolved after
50 million years on land
silurian (blank) evolved 430 mya
tracheid
tracheids are (blank)
water conducting elements of xylem
components of the vascular system
- xylem
- phloem
xylem
water and minerals from soil (up)
phloem
products of photosynthesis (down)
xylem cell walls have (blank)
lignin
tall plant advantage
more light, spore dispersal
- carboniferous period (350-300 mya) vascular plants fluorished in tropical swamps
- millions of years later, coal
vascular plants (lycophytes, horsetails, ferns)
the fall of vascular (seedless, flowerless) plants
- extensive glaciation
- forests were replaced by gymnosperms
- branching, nutritionally independent
- familiar form
sporophytes
- strobili
- mycrophylis
- true roots
phylum lycophyta (club mosses)
clusters containing spores
strobili
simple, lifelike structures (spirals on stem)
mycrophylis
- leaves grow in whorls
- silica in cell walls
- have true roots
phylum sphenophyta (horsetails)
phylum sphenophyta genus
equisetum
- leaves may grow up to 30 m
- spores within sori underside leaves
phylum pterophyta (ferns)
ferns+horsetails+seed plants=
euphyliophytes
ferns + horsetails =
clade monilophytes
monilophytes+seed plants=
euphyilophytes (true + leaf plant)
overtopping
new branches grow beyond others
Why is overtopping an advantage?
- branches formed photosynthetic tissue (megaphyll)
- increased photosynthetic surface area
- “naked seed”
- ovule not protected by ovary
- seeds not protected by fruit
- angiosperms
gymnosperms
seed plants had two innovations
- woody tissue
- seeds
primary growth direction
up and down
secondary growth direction
left and right
secondary growth
- wood (secondary xylem)
- height (photosynthesis)
2 challenges to living on land
- distribute gametes, progeny
- no water for fertilization and wind for pollination
three major groups of gymnosperms
- cycads (300 species)
- gingkos (one living species- Gingko Biloba)
- Conifers (700 species)
alternation of generations in list form
- diploid (2n)
- microstrobili
- meiosis
- habloid
- microspores
- pollen grain
- female gametophyte
- fertilization
- zygote
- embryo
- sporophyte
pollination
pollen grain lands near a female gametophyte
fertilization
sperm meets egg
pollination steps
- pollen tube tunnels to megagametophyte
- entry through microphyle
- sperm released from tube
seed coat
derived from integument; parental sporophyte tissue
food supply
female gametophyte tissue (n)
embryo
new sporophyte (2n)
3 components of seed
-seed coat, food supply, embryo
seeds have tissues from (blank) generations
3
a (blank) develops from the integument
seed coat
haploid female gametophytic tissue from the next generation contains a (blank) for developing embryo
nutrient supply
the (blank) is the new diploid sporophyte generation
embryo
- seeds are protected resting stages
- may remain viable for many years, germinating when conditions are favorable
- seed coat (2n) protects seeds from dyring out
- many seeds also have adaptations for dispersal
gymnosperm seeds
some conifers have what instead of cones?
soft, fleshy tissue around seeds (not fruit)
angiosperm meaning
“enclosed seed”
what advantages did the evolution of the seed provide seed plants over seedless plants?
dormant and dispersal
what are the 6 synapomorphies of angiosperms?
- flowers
- ovules and seeds enclosed in carpel
- pollen on stigma
- double fertilization
- endosperm- nutritive tissue for embryo (3n)
- fruit
pistil
composed of carpels
one or more carpels for the
pistil
grouped flowers
inflorescence
perfect flowers
have both mega and microsporangia
disadvantage of perfect flowers
self fertilization
advantage of perfect flowers
2 processes complete at once
imperfect flowers
either mega or microsporangia
-monoecious and dioecious
monoecious
male and female flowers occur on same plant
dioecious
male and female flowers occur on different plants
double fertilization process
1) sperm 1 +egg = zygote (2n)
2) sperm 2 + central cell (n+n)= endosperm (3n)
endosperm
nutrition/food for embryo
embryo
early stem and root + 1 or 2 cotyledons
ovary and seeds develop into (blank) after fertilization
fruits
fruit purpose
- protect seeds
- dispersal
most angiosperms are in two clades:
monocots
eudicots
monocots
one cotyledon (palms, grasses, crops, (corn-rice-barely-wheat)
eudicots
two cotyledons (most others, including trees)
How do plants benefit human society?
- produce O2 and remove CO2 from atmosphere
- contribute to soil formation and fertility
- roots hold soil in place, prevent erosion
- moderate local climate
- medicine
plant food benefit
10 crops supply 75% total world calories
What is the difference between pollination and fertilization?
pollination is when the pollen lands on the stigma while fertilization occurs when the male cell fuses with the female cell
Characteristics of wind pollinated plants
no nectar, greater amount of pollen, tend to have tiny flowers, often grass plants, no scent, no bright colors, tend to be taller, often look boring
characteristic of bird pollinated plants
attractive, colorful petals, don’t have a smell, contain nectar, have red color, trumpet shaped flowers
why do plants avoid self-fertilization
to avoid potentially dangerous deleterious recessive traits
how do plants avoid self fertilization?
- stigma may not be activated until all of the male pollen has been taken from flower
- produce male and female flowers on separate ind.
what is the purpose of flower plants?
- petals are advertisements that attract animal messengers
- landing area specific for the flower’s pollinators
what animals can pollinate?
- birds, insects, bats, etc
- there are some cases of mammals such as mice, bats, lemurs, even reptiles such as giant gecko
what are the rewards?
- plant acted as breeding ground, plant offered a place to lay eggs
- nectar, wax gives off a perfume for the bee to mate with females
- nutrition in form of nectar
how do plants “trick” pollinators?
- appearing as a mate to the organism
- appear to be and smell like rotting flesh
what part of dandelions floats through air?
seed attached to fruit
Are fungi unicellular? Plants?
yes, no
Do fungi have a cell wall present? Plants?
yes, yes
Are fungi eukaryotic? Plants?
yes, yes
Are fungi absorptive heterotrophs? Plants?
yes, no
Are fungi saprobic? Plants?
yes, no
Are fungi nitrogen fixers? Plants?
no, no
Can fungi be parasitic? Plants?
yes yes
What is a fungus?
- absorptive heterotrophy
- chitin in cell walls
multicellular fungi:
body is a (blank) composed of tubular filaments called (blank)
mycellium, hyphae
multicellular fungi
hyphae separated with (blank) are called (blank)
septa, septate
hyphae without separation are called (blank)
coenocytic
yeast
- unicellular
- lifestyle
- no hyphae
chytrids
-only fungi with flagella
Zygomycota characteristics and example
- bread mold
- coenocytic hyphae in some or all
- terrestrial
arbuscular mycorrhizal fungi
- hyphae penetrate cell wall of root
- mutualist with plants
- mitigate drought conditions for crops
fungi mycorrhizae
- 80 to 90% of plants have associations with mycorrhizae
- hyphae are coenocytic
ascomycota asexual reproduction
conidia form at tips
ascomycota unicellular
yeast saccharomyces, glucose to ethanol +CO2
how do sac fungus yeast reproduce?
budding
the fruiting body of an ascomycota is called the
ascoma
in mushrooms, (blank) form on specialized structures called gills
basidia
(blank) are to ascomycota as (blank) are to basidiomycota
asci
basidia
Has multicellular diploid generation
Basidiomycota or plant?
plant
Has multicellular haploid generation
basidiomycota or plant?
both
Has multicellular dicharotic generation
basidiomycota or plant?
basidiomycota
sexual reproduction involves males and females
basidiomycota or plant?
plant
sexual reproduction involves mating types
basidiomycota or plant?
basidiomycota
syngamy (fusion of gametes)
basidiomycota or plant?
plant
karyogamy (fusion of nuclei)
basidiomycota or plant?
basidiomycota
plasmogomy (fusion of cytoplasm)
basidiomycota or plant?
basidiomycota
3 ways fungus interacts with environment
- mutualism (+/+)
- commensalism (+/0)- saprobes
- predation (+/-)- parasites
fungi are the principal decomposers of
cellulose, ligin, and keratin
fungi causes human disease such as
ringworm and athlete’s foot
fungi are the most common (blank) in plants
pathogens
roles of fungi
-hyphae invade plant tissues through stomata or wounds
example of predation
fungi trap microscopic nematode with hyphae ring
fungi are used as model organisms because
easily cultured and short generation times
reforestation in relation to fungi
projects must establish the mycorrhizal fungi as well as planting trees
